Recoil starters are used to manually start small internal combustion engines. The best known example of a recoil starter is a lawn mower starter. The use of small internal combustion engines having recoil starters has increased in recent years. Such engines are used on hand-held lawn care implements such as line trimmers, blowers, edgers and cultivators. The recoil starter is a relatively frequent maintenance item on such lawn care implements. One problem that may occur is that the pull rope may become disengaged from the rope spool. Another cause for repair of the recoil starter is breakage or jamming of the recoil spring. Another maintenance detail is wear of the starter gear.
In recent years, the weight and cost of internal combustion engines for hand-held implements has been reduced by providing a half-crank internal combustion engine. An example of this is shown in U.S. Pat. No. 4,356,605, in which a single cylinder is connected to a half-crank crankshaft. In this type of engine, a recoil starter is secured to the forward end of the internal combustion engine at the location where the crank is journalled for rotation. It is not possible to secure the recoil starter to the rear portion of the crankshaft because the crank does not extend through the rear of the internal combustion engine.
Prior art recoil starter devices include statutory invention registration H517 to Sato et al, which discloses a recoil starter having a rope which may be replaced by removing a cover on the recoil case without detaching the recoil drum and spiral spring. The recoil pulley is exposed when the recoil cover is removed from the recoil case. A new rope may be wound on the periphery of the recoil pulley without detaching the recoil pulley from the engine. While this simplifies the approach to repair or replacement of the recoil rope, it is not suited for half-crank internal combustion engines and does not provide a simple method for replacing the recoil spring which drives the rope to a return position.
U.S. Pat. No. 4,732,121 to Miyata et al, describes a recoil starter with a side plate disposed between the recoil spring and the rope spool. The side plate is used to retain the recoil spring when the rope spool is removed for replacement or inspection. This design is again not useful with a half-crank internal combustion engine because it is secured to the rear of the internal combustion engine. Also, no method of simply replacing the recoil spring is provided by this reference.
U.S. Pat. No. 2,926,648 to Hamman discloses a recoil starter assembly which may be disassembled by an operator to replace the rope and make other repairs. This approach is not well suited for a half-crank engine and is subject to many of the disadvantages and complex maintenance procedures which are representative of the prior art.
These and other problems and disadvantages encountered by prior art recoil starter assemblies are addressed by the applicant's invention as summarized below.